Plain text plotting tools.

ploot contains the following tools:

 - ploot-text: show plain text string using larger font thanks to
   braille characters
 - ploot-braille: show graph in the form of braille characters
 - ploot-farbfeld: reads collectd-style comma separated values (CSV)
   and produces a plot in the farbfeld image format (pipe it to ff2png).
   It is an alternative to RRDtool
 - ploot-feed: reads collectd-style comma separated values (CSV) but
   produces a plain text continuous waterfall chart for live monitoring
   in the terminal. it is an alternative to grafana
